JP6691472B2 - Pipe end high pressure sealing jig - Google Patents

Description

  The present invention relates to a high-pressure sealing jig for sealing both ends of each heat transfer tube during a pressure resistance test of a multi-tube heat exchanger.

  In a shell-and-tube heat exchanger for boilers, the working fluid is used under high pressure and high temperature conditions. Therefore, the manufactured heat exchanger is finally subjected to a pressure resistance test, and it is inspected that there is no malfunction as a heat exchanger such as water leakage or insufficient strength at a predetermined pressure.

  The multi-tube heat exchanger is a heat exchanger having a structure in which a large number of heat transfer tubes (tubes) are arranged in a cylindrical body (shell). As the heat transfer tube, a rifle tube whose inner circumferential surface is spirally processed is used to improve strength and corrosion resistance.

  In order to perform a pressure resistance test, it is necessary to seal the end of each heat transfer tube at the joint with a high pressure hose for supplying and discharging high pressure water, and in many cases both ends of the tube are sealed by welding. When sealing the pipe ends by welding in this way, the procedures required for the pressure resistance test are (1) welding work, (2) pressure resistance test, (3) removal of welds, and (4) groove of both ends of heat transfer tube. Processing is required, and the skill and time of the operator are required in many of these steps, which is a factor of increasing the manufacturing cost.

  Therefore, in order to reduce the time and cost, a tube end sealing jig is used to seal the end of the heat transfer tube. As such a sealing jig, there is a plug that clamps and seals the outer surface of the rifle tube (see, for example, Patent Document 1).

US Pat. No. 5,676,174 Japanese Utility Model Publication No. 57-105948 Japanese Utility Model Publication No. 57-92149

  The conventional sealing jig as described above has a structure in which the rifle tube is clamped and sealed from the outside, and it is necessary to further have a retaining mechanism that resists the high pressure in the tube during the pressure resistance test. It is difficult to downsize. Therefore, such a sealing jig is not practical because adjacent sealing jigs interfere with each other when the pipe pitch in the body is narrow.

  On the other hand, a method of engaging the rifle tube on the inner surface side has also been proposed (see Patent Documents 2 and 3). However, in the case of this method, it is necessary to manufacture the sealing jig so that the engaging portion fits into the life ring shape of the inner peripheral surface of the pipe, which lacks versatility and economy.

  In view of the above-mentioned problems, an object of the present invention is to fix a heat transfer tube from the outside and to use it for a heat transfer tube arranged at a narrow tube pitch in a fuselage, which is usable for a tube end high pressure seal cure. To provide the ingredients.

In order to achieve the above object, a pipe end high-pressure sealing jig according to the invention of claim 1 is provided with a high-pressure hose for sealing an end of a heat transfer tube of a multi-tube heat exchanger while sealing the end. In a pipe end high pressure sealing jig equipped with a plug having a flow path for introducing high pressure fluid,
A pair of collet members for clamping the outer peripheral surfaces of the heat transfer tubes so as to oppose each other only in the tube diameter direction with respect to the ends thereof, and a heat transfer tube central axis slidable from the outside to the pair of collet members. A sleeve member around which a fitting hole is formed to be fitted so as to be relatively non-rotatable, and a connecting mechanism for connecting the sleeve member and the plug,
The outer wall surfaces of the pair of collet members facing each other form a pair of tapered surfaces whose outer diameter gradually decreases toward the tube center side in the heat transfer tube axial direction,
On the inner wall surface of the fitting hole of the sleeve member, there are formed tapered surfaces slidably abutting each other at the same inclination angle as the tapered surfaces of the pair of collet members,
The pair of collet members, the spacing of each other by moving the tube center side along the heat transfer tube axis direction with respect to the sleeve member is reduced state, and are not tightened end of the heat transfer tube,
The tube diameter direction in which the pair of collet members are opposed to each other is a vertical direction in a state in which the multi-tube heat exchanger of the heat transfer tube is arranged in the body,
The member thickness in the horizontal direction is smaller than the vertical direction of the pipe end high-pressure sealing jig, and the distance D from the center of the pipe end high-pressure sealing jig to the position having the maximum outer diameter in the horizontal direction is adjacent in the horizontal direction. It is characterized in that it is 1/2 or less of the pitch P between the central axes of the heat transfer tubes which are matched with each other .

A pipe end high pressure sealing jig according to a second aspect of the present invention is the pipe end high pressure sealing jig according to the first aspect, wherein the contour of the fitting hole of the sleeve member and the outer shape of the pair of collet members are provided. Is characterized in that the cross-sectional shape in the direction orthogonal to the central axis of the heat transfer tube is substantially rectangular .

  The pipe end high-pressure sealing jig according to the invention described in claim 3 is the pipe end high-pressure sealing jig according to claim 1 or 2, wherein the pair of collet members is the outer circumference of the end of the heat transfer pipe. A plurality of protruding portions forming a tooth-like shape with a sharp tip at least in a cross section along the axial direction of the heat transfer tube are provided on the inner peripheral surface in contact with the surface.

  The pipe end high-pressure sealing jig according to the invention described in claim 4 is the pipe end high-pressure sealing jig according to any one of claims 1 to 3, wherein the pair of collet members are spaced from each other. Is further provided so as to be changeably connected to the sleeve member so as to be slidable integrally with the sleeve member.

The pipe end high-pressure sealing jig according to the invention described in claim 5 is the pipe end high-pressure sealing jig according to any one of claims 1 to 4, wherein the plug is an end of the heat transfer pipe. A cylindrical mounting portion that fits movably in the axial direction of the heat transfer tube and that has an end edge abutting the outer end surfaces of the pair of collet members,
By the movement of the plug toward the center of the tube along the axial direction of the heat transfer tube, the end edge of the cylindrical mounting portion is pushed into the outer end surface, and the pair of collet members are connected to the sleeve member with respect to the heat transfer tube. It is moved in the direction of tightening the end of the.

  In the pipe end high-pressure sealing jig of the present invention, since the pipe outer peripheral surface is clamped only by a pair of collet members facing each other in the pipe diameter direction with respect to the heat transfer pipe end, the pipe end high-pressure sealing jig is The member thickness increases in the pipe diameter direction only, and the member thickness can be kept small in the area around the pipe end where there is no other collet member, and the pipe end high-pressure sealing jig can be miniaturized. Becomes Therefore, if the region with a small member thickness is positioned between the heat transfer tubes of the multi-tube heat exchanger with a narrow pitch, and the pipe end high-pressure sealing jig is attached, the pipe end is clamped from the outside and sealed. Even with this method, there is an effect that they can be mounted well without interfering with each other.

FIG. 3 is a schematic cross-sectional view showing a pipe end high-pressure sealing jig according to an embodiment of the present invention in a state in which attachment is completed, (a) is a side cross-sectional view along the heat transfer tube central axis direction, and (b) is a heat transfer tube central axis. (A) is a cross-sectional view taken along the line AA of (a), and (c) is a cross-sectional view taken along the line BB of (a). FIG. 2 is a schematic perspective view showing a member configuration of the tube end high-pressure sealing jig before attachment of the heat transfer tube end, and partially includes a cross section. It is a sectional side view for explaining the heat transfer tube end part attaching process of the tube end part high pressure sealing jig, and (a)-(c) shows the state of each process. FIG. 2 is a schematic perspective view showing a state in which the tube end high-pressure sealing jig of FIG. 1 is attached to a plurality of heat transfer tubes arranged in parallel in a horizontal direction in a body. It is a partial perspective view which shows the collet member at the time of providing many protrusions of a different form from the case of FIGS. 1 and 2 as a protrusion for the removal prevention of the inner peripheral surface of a pair of collet members.

  The present invention relates to a pipe end high-pressure sealing jig in which a plug having a flow path for introducing high-pressure fluid from a high-pressure hose is attached to an end of a heat transfer pipe of a multi-tube heat exchanger while sealing the end. And a pair of collet members for clamping the outer peripheral surfaces of the heat transfer tubes so as to oppose each other in only one tube diameter direction, and a pair of collet members slidably and externally transferred to the pair of collet members. A sleeve member in which a fitting hole is formed around the central axis of the heat pipe so as to be relatively non-rotatable, and a connecting mechanism for connecting the sleeve member and the plug, and the outer wall surfaces of the pair of collet members facing each other are A pair of tapered surfaces whose outer diameter gradually decreases toward the tube center side in the axial direction of the heat transfer tube, and the inner surface of the fitting hole of the sleeve member is provided with the pair of collet members. The same inclination angle as the tapered surface A pair of collet members are slidably in contact with the sleeve member, and the distance between the collet members decreases as the sleeve members move toward the tube center along the axial direction of the heat transfer tube. The end of the heat transfer tube is tightened.

  According to the above configuration, the pipe end high-pressure sealing jig of the present invention has a pair of wedge-shaped fittings between the pipe end outer peripheral surface and the tapered surface of the inner wall surface of the fitting hole of the sleeve member. The pipe end is reliably clamped by the collet member. When the heat transfer tube is mounted on the end of the heat transfer tube during a pressure resistance test of the multi-tube heat exchanger, the tube outer surface is clamped against the tube end by a pair of pipes facing each other in the diameter direction of the tube. Since it is only the collet member of the above, the member thickness of the pipe end high pressure sealing jig including the sleeve member for fitting and tightening the pair of collet members from the outside becomes large only in the clamping direction in the pipe diameter direction. Since the member thickness can be suppressed to be small in the region around the pipe end where no other collet member exists, the pipe end high pressure sealing jig can be downsized.

  Therefore, if the tube end high-pressure sealing jig is installed by positioning the region with a small member thickness in the narrow pitch between the heat transfer tubes arranged in the body, the heat transfer tube is clamped from the outside and sealed. Even if there is, the plugs can be attached to the end portions of the heat transfer tube satisfactorily without interfering with each other, and the plug can be attached in a good sealed state.

  As described above, the pipe diameter direction for clamping the pipe end portion with the pair of collet members opposed to each other is easy to be the vertical direction (vertical direction) with respect to the heat transfer pipe horizontally arranged in the body. . In this case, since the thickness of the member on the left-right direction (horizontal direction) can be reduced, a multi-tube heat conductor in which more heat transfer tubes are arranged in parallel in the horizontal direction and the tube pitch between adjacent heat transfer tubes on the left and right is narrowed Can handle.

  Further, if the arrangement configuration of the heat transfer tubes of the multi-tube heat exchanger to be used is determined in advance, for example, with respect to the pitch P between the central axes of the heat transfer tubes adjacent in the horizontal direction, the tube end portions The distance D from the center of the high-pressure sealing jig to the position having the maximum outer diameter in the horizontal direction may be 1/2 or less of the pitch P. Further, the outer shape of the tube end high-pressure sealing jig is substantially the outer shape of the sleeve member, and the cross-sectional shape in the direction orthogonal to the heat transfer tube central axis is substantially rectangular so that they can be arranged in parallel with each other efficiently. Preferably.

  Further, the contour of the fitting hole of the sleeve member and the outer shapes of the pair of collet members are also configured such that the cross-sectional shape in the direction orthogonal to the central axis of the heat transfer tube is substantially rectangular, so that the pair of collet members becomes the sleeve member. On the other hand, rotation around the central axis of the heat transfer tube is avoided, and a good tightened state with respect to the tube end can be maintained.

  It should be noted that the tightening position can be more surely held by subjecting the inner peripheral surfaces of the pair of collet members to the outer peripheral surfaces of the pipe end portions so as not to come off. For example, the retaining means can be configured by providing a plurality of protrusions that form a toothed shape with a sharp tip at least in a cross section along the axial direction of the heat transfer tube, on the inner peripheral surfaces of the pair of collet members. In this case, the tooth-shaped tip of each protruding part bites into the outer peripheral surface of the pipe to prevent it from coming off.Therefore, the force that pushes out the pipe end high-pressure sealing jig from the pipe end when introducing high-pressure water during a pressure resistance test. Despite the action, the good tube end clamped state by the pair of collet members is maintained against this. As such a protrusion, a large number of conical or pyramidal protrusions may be formed on the inner peripheral surface of the collet member. Further, not limited to such protrusions, for example, a configuration in which a plurality of protrusions having a substantially triangular cross-section extending in a direction orthogonal to the axial direction of the heat transfer tube are arranged in parallel, the protrusions have a sawtooth shape in a cross section along the axial direction of the heat transfer tube. In this case, the tip ridges of the ridges bite into the outer peripheral surface of the pipe to prevent them from coming off.

  Further, when the pair of collet members are formed as separate members independent from each other, it is necessary to slide integrally with the sleeve member in the axial direction of the heat transfer tube so that the collet members are evenly tightened with respect to the tube end portion. Therefore, a retainer member that connects the pair of collet members to each other may be provided. When the pair of collet members move in the direction in which the inner diameter decreases with respect to the tapered surface of the sleeve member for tightening, the distance between them becomes slightly smaller, so the retainer member has a structure capable of coping with the change in the distance. To do.

  For example, there is a C-shaped retainer ring in which a groove is formed on the inner peripheral surfaces of a pair of collet members at the same position around the axis of the heat transfer tube, and is slidably housed in this groove. The retainer ring is elastically deformed by pressing the pair of collet members so as to reduce the opening distance of the C-shaped member and reduce the diameter, thereby allowing the pair of collet members to be connected while allowing a change in the distance between them. .

  In the pressure resistance test, a plug to which a high-pressure hose for supplying and discharging high-pressure fluid is connected is attached to the end of each heat transfer tube via a tube-end high-pressure sealing jig. Therefore, the pipe end high-pressure sealing jig of the present invention also has a connecting mechanism for connecting the plug having the high-pressure fluid introduction path to the sleeve member.

  Such a connecting mechanism has the same outer shape as that of the sleeve member and is coaxially connected to the sleeve member by screwing or the like, and at the same time, a female screw hole to be screwed into the outer peripheral surface on one end side of the plug is formed in the center. The structure of the cover member is simple.

  The plug has a cylindrical mounting portion that is fitted to the outer periphery of the end portion of the heat transfer tube on the inner peripheral surface so as to be movable in the axial direction of the heat transfer tube, and has a cylindrical mounting portion that is externally threaded on the outer peripheral surface. Is mounted on the outer peripheral surface of the end portion of the heat transfer tube, which is connected to the sleeve member by being screwed into the female screw hole from the one end side and projects through between the pair of collet members in the fitting hole of the sleeve member. It

  In this configuration, by making the female screw hole of the cover member a through hole, one end side of the plug can penetrate the cover member and reach the outer end faces of the pair of collet members in the fitting hole of the sleeve member. Therefore, with this configuration, the end edge of the cylindrical mounting portion of the plug presses the outer end surfaces of the pair of collet members by advancing the screwing of the plug and moving the plug toward the center side of the pipe, and the pair of collet members is pressed. The member can be pushed into the sleeve member in the direction in which the tube end is tightened, and at the same time when the plug is mounted, the tightening of the pair of collet members to the tube end can be completed.

  As an embodiment of the present invention, FIGS. 1 to 4 show a pipe end high-pressure sealing jig that is clamped and attached to a heat transfer pipe of a multi-tube heat exchanger from above and below. FIG. 1 is a schematic cross-sectional view of a main pipe end high-pressure sealing jig showing a state where attachment is completed with respect to the pipe end, (a) is a side cross-sectional view along the heat transfer pipe central axis direction, and (b) is (A) AA cross-section arrow view of the direction orthogonal to a heat transfer tube central axis, (c) is a BB cross-section arrow view of (a). FIG. 2 is a schematic perspective view showing a member configuration of the main pipe end high-pressure sealing jig before the pipe end is attached, and partially includes a cross section. FIG. 3 is a side cross-sectional view showing each step of the pipe end attaching process of the main pipe high pressure sealing jig. FIG. 4 is a schematic perspective view showing a state in which a main tube end high-pressure sealing jig is attached to each of a plurality of heat transfer tubes arranged in parallel in the horizontal direction in the body.

  The tube end high-pressure sealing jig 1 according to the present embodiment includes a pair of collet members (10a, 10b) for clamping the outer peripheral surfaces of the heat transfer tubes 2 so as to oppose each other in only one tube diameter direction. And a sleeve member 15 in which a fitting hole 16 is formed that is fitted to the pair of collet members so as to be slidable from the outside and relatively non-rotatable around the heat transfer tube axis, and the sleeve member 15 and the plug 3 are connected to each other. And a pair of tapered surfaces (11a, 11b) whose opposing outer wall surfaces of the pair of collet members (10a, 10b) gradually decrease in outer diameter along the heat transfer tube axial direction toward the tube center side. ), And the tapered surfaces (17a, 17a, 11a, 11a, 11a, 11b) slidably abutting the inner wall surface of the fitting hole 16 of the sleeve member 15 at the same inclination angle as the tapered surfaces (11a, 11b) of the pair of collet members. 17b) The pair of collet members (10a, 10b) move toward the tube center side with respect to the sleeve member 15 along the axial direction of the heat transfer tube, so that the distance between them becomes small, and the end portions of the heat transfer tube are formed. Is to tighten.

  Specifically, in the tube end high-pressure sealing jig 1, first, a rifle tube 2 as a heat transfer tube is inserted between and the outer peripheral surfaces of the ends are clamped so as to face each other in the vertical diametrical direction of the rifle tube 2. A pair of collet members (10a, 10b), and a sleeve member 15 in which a fitting hole 16 that slidably fits from the outside is formed in the pair of collet members (10a, 10b). .

  As for the outer shape of the pair of collet members (10a, 10b), the upper and lower outer wall surfaces facing each other form a pair of tapered surfaces (11a, 11b) whose outer diameter gradually decreases toward the center of the pipe, and the rifle. The cross-sectional shape in the direction orthogonal to the tube central axis has a substantially rectangular shape with chamfered four corners. The inner peripheral shape of the corresponding fitting hole 16 of the sleeve member 15 is a substantially rectangular cross-sectional shape in the direction orthogonal to the rifle tube central axis so as to follow the outer shape of the pair of collet members (10a, 10b). At the same time, the upper and lower inner wall surfaces are tapered surfaces (17a, 17b) slidably abutting each other at the same inclination angle as the upper and lower tapered surfaces (11a, 11b) of the pair of collet members.

  Since the pair of collet members (10a, 10b) and the fitting hole 16 have a substantially rectangular cross-section, the relative rotation of the two collet members (10a, 10b) around the rifle tube center axis is restricted, and the pair of collet members (10a, 10b) is prevented. The tightening on the rifle tube 2 becomes more stable.

  Further, in the present embodiment, a plurality of protrusions 12 having a substantially triangular shape in cross section along the axial direction of the rifle tube are provided in parallel on the inner peripheral surfaces of the pair of collet members (10a, 10b). These ridges 12 form a sawtooth shape in which a toothed shape with a sharp tip is continuous in a cross section along the axial direction of the rifle tube, so that the tube end high-pressure sealing jig 1 is pushed back to the outside of the tube during a pressure resistance test. Even when pressure is applied to the ridge 12, the tightened state is more firmly maintained due to the effect of retaining the tips of the protrusions 12 from the outer peripheral surface of the rifle tube 2.

  Further, grooves 13 are formed on the inner peripheral surfaces of the pair of collet members (10a, 10b) at the same position in the axial direction of the rifle tube along the circumferential direction, and the C-shaped retainer ring is formed in the grooves 13. 14 is slidably stored. By the retainer ring 14, the pair of collet members (10a, 10b) are connected to each other along the central axis direction of the rifle tube while the spacing between the pair of collet members (10a, 10b) is changed due to tightening. Integrate movement.

  In the main pipe end high-pressure sealing jig 1, a cover member 18 having the same outer shape as the sleeve member 15 is screwed to the sleeve member 15 as a connecting mechanism for the plug 3 for connecting the high-pressure hose H. A through-hole-shaped female screw hole 19 is formed in the center of the cover member 18.

  On the other hand, the plug 3 having the flow path 33 through which the high-pressure water from the high-pressure hose H is introduced has a cylindrical mounting portion 31 that is fitted to the outer periphery of the end portion of the rifle tube 2 on the side opposite to the connection side with the high-pressure hose H. have. An O-ring R is arranged on the inner peripheral surface of the cylindrical mounting portion 31, and an external thread 32 for screwing into the female screw hole 19 of the cover member 18 is provided on the outer peripheral surface.

  Therefore, the plug 3 is connected to the sleeve member 15 by being screwed into the female screw hole 19 of the cover member 18 from one end side, and the plug 3 has a pair of collet members (10 a, 10 b) in the fitting hole 16 of the sleeve member 15. It is attached to the outer peripheral surface of the end portion of the rifle tube 2 which projects through the space. In this embodiment, the end edge F2 of the cylindrical mounting portion 31 of the plug 3 is passed through the female screw hole 19 of the cover member 18 so that the outer edge face F1 of the pair of collet members (10a, 10b). It is configured to abut.

  To mount the tube end high-pressure sealing jig 1 having the above-described configuration, first, as shown in FIG. 3A, the pair of collet members (10a, 10b) are arranged in the through hole 16 of the sleeve member 15, and the sleeve member The plug 3 is screwed to some extent in the female screw hole 19 of the cover member 18 screwed to the cover member 15 (not shown for simplification of the drawing) so that the constituent members are integrated. Then, the rifle tube 2 is inserted from between the pair of collet members (10a, 10b) until it penetrates the cover member 18, and the tube end portion is fitted into the inner circumference of the cylindrical mounting portion 31 of the plug 3 (see FIG. b)).

  After that, the screwing of the plug 3 is advanced and moved toward the tube center side along the axial direction of the heat transfer tube, so that the end edge F2 of the cylindrical mounting portion 31 of the plug 3 has a pair of collet members (10a, 10b). By pressing the outer end face F1 of the plug member, the pair of collet members (10a, 10b) can be pushed into the sleeve member 15 in the direction of tightening the pipe end portion, and as shown in FIG. At the same time as the mounting, the pipe end high-pressure sealing jig 1 is completely attached by tightening the pair of collet members (10a, 10b) to the pipe ends.

  In the present embodiment, the outer shape of the tube end high-pressure sealing jig 1, that is, the outer shape of the sleeve member 15 and the cover member 18 is a rectangular cross-section with the vertical direction being the long side direction. With respect to the pitch P between the central axes of the rifle tubes 2 which are horizontally adjacent to each other in the body of the body, the distance D from the center of the tube end high-pressure sealing jig 1 to the position having the maximum outer diameter in the horizontal direction is set. , 1/2 of pitch P or less. As a result, as shown in FIG. 4, adjacent tube end high-pressure sealing jigs 1 can be favorably attached to a large number of rifle tubes 2 without interfering with each other.

  In the above embodiments, a plurality of protrusions having a triangular cross-section extending in the direction orthogonal to the axial direction of the heat transfer tube are arranged in parallel on the inner peripheral surface of the collet member as the protrusions for preventing slippage. Although shown, it is also possible to employ protrusions of other forms. For example, as shown in FIG. 5, it is also desirable that a large number of conical or pyramidal protrusions 42 having sharp tips are formed. In this case, a large number of point-like biting points with respect to the outer peripheral surface of the pipe are secured.

1: Pipe end high-pressure sealing jig 2: Rifle pipe (heat transfer pipe)
3: Plugs 10a, 10b: Collet members 11a, 11b: Tapered surface 12: Protrusion 13: Groove 14: Retainer ring 15: Sleeve member 16: Fitting holes 17a, 17b: Tapered surface 18: Cover member 19: Female screw hole 31 : Cylindrical mounting part 32: Male thread processing 33: Flow path 42: Protrusion R: O-ring F1: Outer end faces F2 of a pair of collet members: Edges of cylindrical mounting part of plug H: High pressure hose

Claims (5)

At the end of the heat transfer tube of the multi-tube heat exchanger, a tube end high-pressure sealing jig, in which a plug having a flow path for introducing high-pressure fluid from a high-pressure hose while sealing the end is mounted,
A pair of collet members for clamping the outer peripheral surfaces of the heat transfer tubes so as to face each other in only one tube diameter direction with respect to the end portions of the heat transfer tubes, and the pair of collet members being slidable from the outside in the heat transfer tube axial direction. And a sleeve member in which a fitting hole is formed around the center axis of the heat transfer tube so as to be relatively non-rotatable, and a connecting mechanism that connects the sleeve member and the plug,
The outer wall surfaces of the pair of collet members facing each other form a pair of tapered surfaces whose outer diameter gradually decreases toward the tube center side in the heat transfer tube axial direction,
On the inner wall surface of the fitting hole of the sleeve member, there are formed tapered surfaces slidably abutting each other at the same inclination angle as the tapered surfaces of the pair of collet members,
The pair of collet members, the spacing of each other by moving the tube center side along the heat transfer tube axis direction with respect to the sleeve member is reduced state, and are not tightened end of the heat transfer tube,
The tube diameter direction in which the pair of collet members are opposed to each other is a vertical direction in a state in which the multi-tube heat exchanger of the heat transfer tube is arranged in the body,
The member thickness in the horizontal direction is smaller than the vertical direction of the pipe end high-pressure sealing jig, and the distance D from the center of the pipe end high-pressure sealing jig to the position having the maximum outer diameter in the horizontal direction is adjacent in the horizontal direction. A pipe end high-pressure sealing jig having a pitch P between the central axes of the heat transfer pipes that are matched to each other is 1/2 or less . The pipe end high pressure according to claim 1, wherein the contour of the fitting hole of the sleeve member and the outer shape of the pair of collet members are substantially rectangular in cross section in a direction orthogonal to the central axis of the heat transfer tube. Seal jig.   The pair of collet members has a plurality of protruding portions that form a toothed shape with a sharp tip at least in a cross section along the axial direction of the heat transfer tube, on an inner peripheral surface that abuts an outer peripheral surface of an end portion of the heat transfer tube. The pipe end high-pressure sealing jig according to claim 1 or 2, further comprising:   4. A retainer member for connecting the pair of collet members so that the distance between them can be changed so as to be slidable integrally with the sleeve member. The high-pressure sealing jig for a pipe end according to item 1. The plug includes a cylindrical mounting portion that fits movably in an axial direction of the heat transfer tube on an outer periphery of an end portion of the heat transfer tube and has an end edge thereof abutting an outer end surface of the pair of collet members,
By the movement of the plug toward the center of the tube along the axial direction of the heat transfer tube, the end edge of the cylindrical mounting portion is pushed into the outer end surface, and the pair of collet members are connected to the sleeve member with respect to the heat transfer tube. The pipe end high-pressure sealing jig according to any one of claims 1 to 4, wherein the end of the pipe is moved in a tightening direction.

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